Re: [bolger] Small Boats & Lightning Strikes
On 8/5/05, ANDREW AIREY <andyairey@...> wrote:
"We lost LM2 when it was strck by lighting during the tail end of what was a
near miss hurricane which literally melted our mooring chain and LM@
wound up on the rocks in 12 foot seas and by the time that we were able to
get her off (three days) it was pretty much a total loss...As they say shit
happens. By the way several other boats were lost at the same time including
a couple of big fiberglass boats and a steel cutter ( Loose Moose was actually
in better shape than those as it happens...)"
> What happened to LoosemooseII? Wasn't that destroyedBob Wise told me earlier this year that:
> by lightning
> Andy Airey
"We lost LM2 when it was strck by lighting during the tail end of what was a
near miss hurricane which literally melted our mooring chain and LM@
wound up on the rocks in 12 foot seas and by the time that we were able to
get her off (three days) it was pretty much a total loss...As they say shit
happens. By the way several other boats were lost at the same time including
a couple of big fiberglass boats and a steel cutter ( Loose Moose was actually
in better shape than those as it happens...)"
A 40 foot ketch was destroyed by lightning here in Kingston harbour
this week.
She was struck at the entrance to the breakwater, caught fire and
burned. The skipper had to bail, the burning fibreglass fumes were
thick and noxious. Boat remained floating and fire was extinguished by
the fire dept and Coast Guard. A phot of it burning was in the paper
and the hulk, still shaped like a boat but black and crispy is in a
boatyard slip. Toasty.
This was only 150 yards from a shorline lined with 10 story hotels and
condos.
You never know.
Bruce Hector
this week.
She was struck at the entrance to the breakwater, caught fire and
burned. The skipper had to bail, the burning fibreglass fumes were
thick and noxious. Boat remained floating and fire was extinguished by
the fire dept and Coast Guard. A phot of it burning was in the paper
and the hulk, still shaped like a boat but black and crispy is in a
boatyard slip. Toasty.
This was only 150 yards from a shorline lined with 10 story hotels and
condos.
You never know.
Bruce Hector
What happened to LoosemooseII? Wasn't that destroyed
by lightning
Krs
Andy Airey
--- graeme19121984 <graeme19121984@...>
wrote:
---------------------------------
That Matt Layden takes the trouble, right from the
outset, of
incorporating a grounded mast top lightning conductor
into quite
small boat designs, such as Parodox, caught my
attention when I
first saw sketches on the net. I've heard that by no
means the book
on lightning theory is yet closed.
I wouldn't set out to sail my small dinghy in a
thunder storm, but I
have been caught out.
For what its worth: "...Dr Thompson offers the
awareness that most
boat lightning fatalities occur in small open boats."
writes Arlyn
Stewart (16th para):
http://www.stewartfam.net/arlyn/lightning2.html
http://tinyurl.com/7b9xn
I hadn't even thought of how the different
circumstances presented
by small boats, and by fresh water, might suggest a
different
approach to lightning strike management. I just
thought the usual
applied: boat on salt water + cone of protection +
bonding + etc.
The mast conductor to long narrow ground plate used by
M Layden may
not transfer to be the best solution in all small
boats. What do
people think of Arlyn Stewart's ideas (pasted below
from his webpage
paragraphs 49 & 48) of using welding cable with an
arrestor? Is this
also useful for the same type of boat in salt water?
"Arrestor
Is keeping the mast ungrounded the simple answer for a
small boat in
fresh water? No. A ground system would likely reduce
damage and side
flashing if the mast does take a hit. How can there be
a ground
system without grounding the mast? By use of an
arrestor, a small
air gap or dielectric that will provide for an
isolated mast but yet
provide a bridge to a lightning protection system.
Will the
lightning still hit the mast if its not grounded? Yes,
statistics
indicate that the ungrounded mast while less likely to
be hit will
still take the hit. In my early survey conclusions,
100% of
sailboats that were hit either grounded or ungrounded,
took the hit
to the mast. Because ground systems in small
freshwater sailboats
are likely inadequate, its unwise to attract lightning
to them, so
using an arrestor makes sense. The arrestor should be
placed in the
ground conducting path from the mast base to the
water. On a small
boat in fresh water, it has been suggested that the
most effective
ground is a long copper strip. Small boats however
need something
flexible and easy to store.
One idea is to use copper welding cable. Not only
would it meet the
easy to store requirement, but It would be very quick
and easy to
deploy when needed. With 8-10 feet of bare wire on
each end and the
insulation left on the out of water section, the wire
would be
wrapped a couple of turns around the base of the mast
and then each
end draped over the sides passing against the side
shrouds being
sure that the stripped sections are not against the
shrouds. The
ends would of necessity need to be as long as
possible, but short of
the outboard prop. The insulation left on the cable
becomes the
arrestor, keeping the mast ungrounded but yet
providing a short
bridge to carry the hit to the grounding wire. Some
small holes in
the insulation where it wraps around the mast would
provide a spark
gap while holding the cable from bonding. With two
turns of cable
around the mast and equal sections on each side, the
rubber covered
cable shouldn't need any further effort to remain in
place. This
would afford twenty feet of ground strap, a good
conductor without
connections and an arrestor which should provide a
ready pickup for
a lightning discharge. " (A Stewart)
I've seen provision made in some of PCB's larger
designs. Have PCB&F
detailed lightning strike management considerations in
any small
boat plans?
Graeme
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging
dead horses
- stay on topic, stay on thread, punctuate, no 'Ed,
thanks, Fred' posts
- Pls add your comments at the TOP, SIGN your posts,
and snip away
- Plans: Mr. Philip C. Bolger, P.O. Box 1209,
Gloucester, MA, 01930, Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
- Open discussion:
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---------------------------------
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by lightning
Krs
Andy Airey
--- graeme19121984 <graeme19121984@...>
wrote:
---------------------------------
That Matt Layden takes the trouble, right from the
outset, of
incorporating a grounded mast top lightning conductor
into quite
small boat designs, such as Parodox, caught my
attention when I
first saw sketches on the net. I've heard that by no
means the book
on lightning theory is yet closed.
I wouldn't set out to sail my small dinghy in a
thunder storm, but I
have been caught out.
For what its worth: "...Dr Thompson offers the
awareness that most
boat lightning fatalities occur in small open boats."
writes Arlyn
Stewart (16th para):
http://www.stewartfam.net/arlyn/lightning2.html
http://tinyurl.com/7b9xn
I hadn't even thought of how the different
circumstances presented
by small boats, and by fresh water, might suggest a
different
approach to lightning strike management. I just
thought the usual
applied: boat on salt water + cone of protection +
bonding + etc.
The mast conductor to long narrow ground plate used by
M Layden may
not transfer to be the best solution in all small
boats. What do
people think of Arlyn Stewart's ideas (pasted below
from his webpage
paragraphs 49 & 48) of using welding cable with an
arrestor? Is this
also useful for the same type of boat in salt water?
"Arrestor
Is keeping the mast ungrounded the simple answer for a
small boat in
fresh water? No. A ground system would likely reduce
damage and side
flashing if the mast does take a hit. How can there be
a ground
system without grounding the mast? By use of an
arrestor, a small
air gap or dielectric that will provide for an
isolated mast but yet
provide a bridge to a lightning protection system.
Will the
lightning still hit the mast if its not grounded? Yes,
statistics
indicate that the ungrounded mast while less likely to
be hit will
still take the hit. In my early survey conclusions,
100% of
sailboats that were hit either grounded or ungrounded,
took the hit
to the mast. Because ground systems in small
freshwater sailboats
are likely inadequate, its unwise to attract lightning
to them, so
using an arrestor makes sense. The arrestor should be
placed in the
ground conducting path from the mast base to the
water. On a small
boat in fresh water, it has been suggested that the
most effective
ground is a long copper strip. Small boats however
need something
flexible and easy to store.
One idea is to use copper welding cable. Not only
would it meet the
easy to store requirement, but It would be very quick
and easy to
deploy when needed. With 8-10 feet of bare wire on
each end and the
insulation left on the out of water section, the wire
would be
wrapped a couple of turns around the base of the mast
and then each
end draped over the sides passing against the side
shrouds being
sure that the stripped sections are not against the
shrouds. The
ends would of necessity need to be as long as
possible, but short of
the outboard prop. The insulation left on the cable
becomes the
arrestor, keeping the mast ungrounded but yet
providing a short
bridge to carry the hit to the grounding wire. Some
small holes in
the insulation where it wraps around the mast would
provide a spark
gap while holding the cable from bonding. With two
turns of cable
around the mast and equal sections on each side, the
rubber covered
cable shouldn't need any further effort to remain in
place. This
would afford twenty feet of ground strap, a good
conductor without
connections and an arrestor which should provide a
ready pickup for
a lightning discharge. " (A Stewart)
I've seen provision made in some of PCB's larger
designs. Have PCB&F
detailed lightning strike management considerations in
any small
boat plans?
Graeme
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging
dead horses
- stay on topic, stay on thread, punctuate, no 'Ed,
thanks, Fred' posts
- Pls add your comments at the TOP, SIGN your posts,
and snip away
- Plans: Mr. Philip C. Bolger, P.O. Box 1209,
Gloucester, MA, 01930, Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
- Open discussion:
bolger_coffee_lounge-subscribe@yahoogroups.com
SPONSORED LINKS
Boating magazine
Boating safety
Alaska outdoors
Great outdoors
---------------------------------
YAHOO! GROUPS LINKS
Visit your group "bolger" on the web.
To unsubscribe from this group, send an email to:
bolger-unsubscribe@yahoogroups.com
Your use of Yahoo! Groups is subject to the Yahoo!
Terms of Service.
---------------------------------
___________________________________________________________
How much free photo storage do you get? Store your holiday
snaps for FREE with Yahoo! Photoshttp://uk.photos.yahoo.com
That Matt Layden takes the trouble, right from the outset, of
incorporating a grounded mast top lightning conductor into quite
small boat designs, such as Parodox, caught my attention when I
first saw sketches on the net. I've heard that by no means the book
on lightning theory is yet closed.
I wouldn't set out to sail my small dinghy in a thunder storm, but I
have been caught out.
For what its worth: "...Dr Thompson offers the awareness that most
boat lightning fatalities occur in small open boats." writes Arlyn
Stewart (16th para):
http://www.stewartfam.net/arlyn/lightning2.html
http://tinyurl.com/7b9xn
I hadn't even thought of how the different circumstances presented
by small boats, and by fresh water, might suggest a different
approach to lightning strike management. I just thought the usual
applied: boat on salt water + cone of protection + bonding + etc.
The mast conductor to long narrow ground plate used by M Layden may
not transfer to be the best solution in all small boats. What do
people think of Arlyn Stewart's ideas (pasted below from his webpage
paragraphs 49 & 48) of using welding cable with an arrestor? Is this
also useful for the same type of boat in salt water?
"Arrestor
Is keeping the mast ungrounded the simple answer for a small boat in
fresh water? No. A ground system would likely reduce damage and side
flashing if the mast does take a hit. How can there be a ground
system without grounding the mast? By use of an arrestor, a small
air gap or dielectric that will provide for an isolated mast but yet
provide a bridge to a lightning protection system. Will the
lightning still hit the mast if its not grounded? Yes, statistics
indicate that the ungrounded mast while less likely to be hit will
still take the hit. In my early survey conclusions, 100% of
sailboats that were hit either grounded or ungrounded, took the hit
to the mast. Because ground systems in small freshwater sailboats
are likely inadequate, its unwise to attract lightning to them, so
using an arrestor makes sense. The arrestor should be placed in the
ground conducting path from the mast base to the water. On a small
boat in fresh water, it has been suggested that the most effective
ground is a long copper strip. Small boats however need something
flexible and easy to store.
One idea is to use copper welding cable. Not only would it meet the
easy to store requirement, but It would be very quick and easy to
deploy when needed. With 8-10 feet of bare wire on each end and the
insulation left on the out of water section, the wire would be
wrapped a couple of turns around the base of the mast and then each
end draped over the sides passing against the side shrouds being
sure that the stripped sections are not against the shrouds. The
ends would of necessity need to be as long as possible, but short of
the outboard prop. The insulation left on the cable becomes the
arrestor, keeping the mast ungrounded but yet providing a short
bridge to carry the hit to the grounding wire. Some small holes in
the insulation where it wraps around the mast would provide a spark
gap while holding the cable from bonding. With two turns of cable
around the mast and equal sections on each side, the rubber covered
cable shouldn't need any further effort to remain in place. This
would afford twenty feet of ground strap, a good conductor without
connections and an arrestor which should provide a ready pickup for
a lightning discharge. " (A Stewart)
I've seen provision made in some of PCB's larger designs. Have PCB&F
detailed lightning strike management considerations in any small
boat plans?
Graeme
incorporating a grounded mast top lightning conductor into quite
small boat designs, such as Parodox, caught my attention when I
first saw sketches on the net. I've heard that by no means the book
on lightning theory is yet closed.
I wouldn't set out to sail my small dinghy in a thunder storm, but I
have been caught out.
For what its worth: "...Dr Thompson offers the awareness that most
boat lightning fatalities occur in small open boats." writes Arlyn
Stewart (16th para):
http://www.stewartfam.net/arlyn/lightning2.html
http://tinyurl.com/7b9xn
I hadn't even thought of how the different circumstances presented
by small boats, and by fresh water, might suggest a different
approach to lightning strike management. I just thought the usual
applied: boat on salt water + cone of protection + bonding + etc.
The mast conductor to long narrow ground plate used by M Layden may
not transfer to be the best solution in all small boats. What do
people think of Arlyn Stewart's ideas (pasted below from his webpage
paragraphs 49 & 48) of using welding cable with an arrestor? Is this
also useful for the same type of boat in salt water?
"Arrestor
Is keeping the mast ungrounded the simple answer for a small boat in
fresh water? No. A ground system would likely reduce damage and side
flashing if the mast does take a hit. How can there be a ground
system without grounding the mast? By use of an arrestor, a small
air gap or dielectric that will provide for an isolated mast but yet
provide a bridge to a lightning protection system. Will the
lightning still hit the mast if its not grounded? Yes, statistics
indicate that the ungrounded mast while less likely to be hit will
still take the hit. In my early survey conclusions, 100% of
sailboats that were hit either grounded or ungrounded, took the hit
to the mast. Because ground systems in small freshwater sailboats
are likely inadequate, its unwise to attract lightning to them, so
using an arrestor makes sense. The arrestor should be placed in the
ground conducting path from the mast base to the water. On a small
boat in fresh water, it has been suggested that the most effective
ground is a long copper strip. Small boats however need something
flexible and easy to store.
One idea is to use copper welding cable. Not only would it meet the
easy to store requirement, but It would be very quick and easy to
deploy when needed. With 8-10 feet of bare wire on each end and the
insulation left on the out of water section, the wire would be
wrapped a couple of turns around the base of the mast and then each
end draped over the sides passing against the side shrouds being
sure that the stripped sections are not against the shrouds. The
ends would of necessity need to be as long as possible, but short of
the outboard prop. The insulation left on the cable becomes the
arrestor, keeping the mast ungrounded but yet providing a short
bridge to carry the hit to the grounding wire. Some small holes in
the insulation where it wraps around the mast would provide a spark
gap while holding the cable from bonding. With two turns of cable
around the mast and equal sections on each side, the rubber covered
cable shouldn't need any further effort to remain in place. This
would afford twenty feet of ground strap, a good conductor without
connections and an arrestor which should provide a ready pickup for
a lightning discharge. " (A Stewart)
I've seen provision made in some of PCB's larger designs. Have PCB&F
detailed lightning strike management considerations in any small
boat plans?
Graeme